1. Field of the Invention
The invention relates to a thermal relay belonging to a range of relays, each comprising in a case current monitoring means capable, when overloads appear, of tripping an armed mechanism and opening a safety switch, and having on a front face of this case :
on the one hand, a first pusher for re-setting the mechanism after tripping,
and on the other hand, a second pusher for artificially opening this safety switch during a testing procedure,
whereas remote control means, comprising electromagnets each having a casing capable of being mechanically associated with the case, each have an actuating member such as a movable plate, a movable armature or a movable core adapted to drive in these pushers.
2. Description of the Prior art
Such relays and eleotromagnets, which are known for example from the Telemecanique catalogue 1987-1988, pages 3/128 and 3/129 of the Applicant, find their application in all the fields where an industrial installation comprises for instance a control and testing desk or post, where information is centralized relative to the appearance of operating faults, and from where electric signals may be emitted for establishing or re-establishing in desired time the start-up of apparatus such as motors, when the conditions for correct operation are brought together again.
For remote re-setting and tripping, the prior art apparatus comprises two separate electromagnets which are each able to carry out one of the above mentioned two operations; the size and the fixing means for the casings of these two electromagnets are such that they cannot be positioned simultaneously. The result is that centralization of the controls for the two above functions cannot be completely provided and that further an additional technical cost must be ascribed to the existence of two separate electromagnet models furthermore requiring separate storage volumes.